Shock: is defined as a state of cellular and tissue hypoxia due to reduced oxygen delivery and/or increased oxygen consumption or inadequate oxygen utilisation.

Types of Hemorrhagic Shock: The American College of Surgeons Advanced Trauma Life Support (ATLS) hemorrhagic shock classification (in a healthy 70 kg patient) as shown in the Table  below.

Class	Type I	Type II	Type III	Type IV
Blood loss(ml)	<750	750-1500	1500-2000	>2000
Blood loss(%)	<15	15-30	30-40	>40
Pulse	<100	100-120	120-140	>140
Blood Pressure	Normal	Normal	Decreased	Decreased
Respiratory rate	12-20	20-30	30-40
Capillary refill	Normal	Decreased	Decreased	Decreased
Urine output (ml/hr)	>30	20-30	5-15	Negligible/ None
Mental status	Slightly anxious	Anxious	Confused	Confused/ Lethargic
Fluid replacement	Crystalloid	Crystalloid	Crystalloid + Blood	Crystalloid + Blood

Also see:

Hemorrhagic Shock (https://www.ncbi.nlm.nih.gov/books/NBK470382/)